On Jun 25, 2012, at 10:20 AM, andre zege wrote: > dput() is intended to be parsed by R so the above is not possible without > massaging the output. But why in the would would you use dput() for something > that you want to read in Java? Why don't you use a format that Java can read > easily - such as JSON? > > Cheers, > Simon > > > > > > Yeap, except i was just working with someone elses choice. Bigmatrix code > uses dput() to dump desc file of filebacked matrices.
Ah, ok, that is indeed rather annoying as it's pretty much the most non-portable storage (across programs) one could come up with. (I presume you're talking about big.matrix from bigmemory?) > I got some time to do a little hack of reading big matrices nicely to java > and was looking to some ways of smoothing the edges of parsing .desc file a > little. I guess i am ok now with parsing .desc with some regex. One thing i > am still wondering about is whether i really need to convert back and forth > between liitle endian and big endian. Namely, java platform has little endian > native byte order, and big matrix code writes stuff in big endian. It'd be > nice if i could manipulate that by some #define somewhere in the makefile or > something and make C++ write little endian without byte swapping every time i > need to communicate with big matrix from java. I think you're wrong (if we are talking about bigmemory) - the endianness is governed by the platform as far as I can see. On little-endian machines the big matrix storage is little endian and on big-endian machines it is big-endian. It's very peculiar that the descriptor doesn't even store the endianness - I think you could talk to the authors and suggest that they include most basic information such as endianness and, possibly, change the format to something that is well-defined without having to evaluate it in R (which is highly dangerous and a serious security risk). Cheers, Simon ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
